This invention relates to a system for pneumatically conveying bulk particulate materials, and more particularly to such a system which may be operated to purge residual material remaining in the transport line thereof following a shutdown of the system.
In a typical system for pneumatically conveying bulk particulate materials from a first site to a second site, there is provided a material feed receptacle located at the first site, a material receiving receptacle located at the second site, a transport line receiving material from the feed receptacle and guiding it to the receiving receptacle and means for injecting air under pressure into the transport line to impel the material fed therein. Such receptacles at either of such sites may consist of storage vessels, processing equipment and various other modes of transportation including truck bodies, railway cars and ship holds.
Often, when the operation of such a system is shut down, a certain amount of material remains in the transport line which may be undesirable. Such condition could result in a distortion of measured amounts of the material being conveyed, a possible degradation of the residual material, a settling of the material causing subsequent blockage of the transport line and depending upon the material being conveyed, a possible undue deterioration of the transport line. Accordingly, it is the principal object of the present invention to provide a system for pneumatically conveying bulk particulate materials in which residual material in the transport line thereof may be readily purged upon shutdown of the system.
The present invention overcomes the problem of the deleterious effects of residual material remaining in the transport line of a pneumatic conveying system by providing a transport line thereof which is operable to return such residual material to the feed receptacle. This is accomplished by providing a transport line which either is provided with permanent means for returning such material to the feed receptacle or can be reconfigured to return such material.